diff --git a/DECISIONS.md b/DECISIONS.md
index 30f763e..51169d5 100644
--- a/DECISIONS.md
+++ b/DECISIONS.md
@@ -273,3 +273,12 @@ Implementation decisions not spelled out in `memory-bank/implementation-plan.md`
 - **Boards are generated and stored on first request** with `INSERT ... ON CONFLICT DO NOTHING` on the unique (player, kind, location, period) key, then re-read, so concurrent first requests end up with one stored board.
 - **Board responses hide accepted contracts** (`accepted_contracts`) and report `periodEndsAt`, when every contract on the board expires.
 - **Tutorial board errors:** `409 not-in-tutorial` once the tutorial is over.
+
+## Step 6.4
+
+- **A tutorial contract must be on one of the player's stored tutorial boards** (found by a JSONB containment query on contract id). Unknown ids return `404 unknown-contract`; ids already in `accepted_contracts` return `409 contract-already-accepted`. A contract from an earlier period is found, and sim then rejects it as `contract-expired`.
+- **The loaner's `ShipState`** is built from `players.loaner_location_id` with id `loaner` and the content Courier model. The dispatch row has `ship_id` null.
+- **While flying, the avatar's stored location is null**; resolution sets it to the destination, along with the loaner's location.
+- **`storeDispatch` is shared by every dispatch kind:** it inserts the dispatch, records the accepted contract, and deducts the record's fuel cost (0 for tutorial runs).
+- **Sim validation reasons are returned as `409` with their own code** and a player-facing message from `src/game/messages.ts`.
+- **`404 unknown-contract` and `404 unknown-skill`** join `not-found` as the codes that map to 404.
diff --git a/apps/server/src/app.ts b/apps/server/src/app.ts
index 5a0c071..72c0db1 100644
--- a/apps/server/src/app.ts
+++ b/apps/server/src/app.ts
@@ -7,6 +7,7 @@ import { registerErrorHandler } from "./http/errors";
 import { requirePlayerId } from "./http/session";
 import type { AppContext } from "./routes/context";
 import { registerBoardRoutes } from "./routes/boards";
+import { registerDispatchRoutes } from "./routes/dispatches";
 import { registerPlayerRoutes } from "./routes/player";
 
 export interface AppDeps {
@@ -41,6 +42,7 @@ export function buildApp(config: ServerConfig, deps: AppDeps = {}): FastifyInsta
   app.get("/api/health", async () => ({ status: "ok" }));
   registerPlayerRoutes(app, ctx);
   registerBoardRoutes(app, ctx);
+  registerDispatchRoutes(app, ctx);
 
   return app;
 }
diff --git a/apps/server/src/game/dispatch.ts b/apps/server/src/game/dispatch.ts
new file mode 100644
index 0000000..ca11ffc
--- /dev/null
+++ b/apps/server/src/game/dispatch.ts
@@ -0,0 +1,187 @@
+import { randomUUID } from "node:crypto";
+import { content } from "@deadhead/content";
+import type { Dispatch } from "@deadhead/schema";
+import {
+  createDispatchRecord,
+  loanerModel,
+  validateDispatch,
+  type Contract,
+  type DispatchRecord,
+  type PilotState,
+  type RealTime,
+  type ShipState,
+} from "@deadhead/sim";
+import { and, eq, sql } from "drizzle-orm";
+import type { Queryable } from "../db/client";
+import {
+  acceptedContracts,
+  companies,
+  contractBoards,
+  dispatches,
+  pilots,
+  players,
+} from "../db/schema";
+import { gameError } from "../http/errors";
+import { acceptedContractIds } from "./boards";
+import { toApiDispatch } from "./mappers";
+import { VALIDATION_MESSAGES } from "./messages";
+
+/** The id the tutorial loaner uses in dispatch records (it is not a ship row). */
+export const LOANER_SHIP_ID = "loaner";
+
+/** Finds a contract on any of the player's stored boards of a kind. */
+export async function findBoardContract(
+  tx: Queryable,
+  playerId: string,
+  kind: "bay" | "tutorial",
+  contractId: string,
+): Promise<{ contract: Contract; periodIndex: number } | undefined> {
+  const [board] = await tx
+    .select()
+    .from(contractBoards)
+    .where(
+      and(
+        eq(contractBoards.playerId, playerId),
+        eq(contractBoards.kind, kind),
+        sql`${contractBoards.contracts} @> ${JSON.stringify([{ id: contractId }])}::jsonb`,
+      ),
+    );
+  const contract = board?.contracts.find((c) => c.id === contractId);
+  return board && contract ? { contract, periodIndex: board.periodIndex } : undefined;
+}
+
+/** Loads a board contract the player may still accept, or throws. */
+export async function claimableContract(
+  tx: Queryable,
+  playerId: string,
+  kind: "bay" | "tutorial",
+  contractId: string,
+): Promise<{ contract: Contract; periodIndex: number }> {
+  const found = await findBoardContract(tx, playerId, kind, contractId);
+  if (!found) throw gameError("unknown-contract", "No such contract on your boards.");
+  if ((await acceptedContractIds(tx, playerId)).has(contractId)) {
+    throw gameError("contract-already-accepted", "That contract has already been taken.");
+  }
+  return found;
+}
+
+export function pilotState(row: typeof pilots.$inferSelect): PilotState {
+  return {
+    id: row.id,
+    isAvatar: row.isAvatar,
+    assignedShipId: row.assignedShipId,
+    inFlight: row.status === "in_flight",
+    skills: row.skills,
+  };
+}
+
+/** Stores a dispatch, marks its contract accepted, and charges fuel. */
+export async function storeDispatch(
+  tx: Queryable,
+  args: {
+    playerId: string;
+    record: DispatchRecord;
+    /** Null for the tutorial loaner. */
+    shipId: string | null;
+    /** The board period the contract came from; null for a reposition. */
+    periodIndex: number | null;
+    now: RealTime;
+  },
+): Promise<Dispatch> {
+  const { playerId, record, shipId, now } = args;
+  const [row] = await tx
+    .insert(dispatches)
+    .values({
+      id: record.id,
+      playerId,
+      shipId,
+      pilotId: record.pilotId,
+      tutorial: record.tutorial,
+      record,
+      arrivalAt: record.arrivalAt,
+    })
+    .returning();
+  if (record.contract && args.periodIndex !== null) {
+    await tx.insert(acceptedContracts).values({
+      playerId,
+      contractId: record.contract.id,
+      periodIndex: args.periodIndex,
+      dispatchId: record.id,
+      acceptedAt: now,
+    });
+  }
+  if (record.fuelCost > 0) {
+    await tx
+      .update(companies)
+      .set({ credits: sql`${companies.credits} - ${record.fuelCost}` })
+      .where(eq(companies.playerId, playerId));
+  }
+  return toApiDispatch(row!);
+}
+
+/**
+ * The avatar flies the company loaner on a tutorial contract (Step 6.4). The
+ * company pays fuel, and only one tutorial run may be in flight.
+ */
+export async function dispatchTutorial(
+  tx: Queryable,
+  playerId: string,
+  contractId: string,
+  now: RealTime,
+): Promise<Dispatch> {
+  const [player] = await tx.select().from(players).where(eq(players.id, playerId));
+  if (!player?.tutorialActive || !player.loanerLocationId) {
+    throw gameError("not-in-tutorial", "The tutorial is over.");
+  }
+  const [running] = await tx
+    .select({ id: dispatches.id })
+    .from(dispatches)
+    .where(
+      and(
+        eq(dispatches.playerId, playerId),
+        eq(dispatches.tutorial, true),
+        eq(dispatches.status, "in_flight"),
+      ),
+    );
+  if (running) throw gameError("tutorial-run-in-flight", "Your tutorial run is still flying.");
+
+  const { contract, periodIndex } = await claimableContract(tx, playerId, "tutorial", contractId);
+  const [avatar] = await tx
+    .select()
+    .from(pilots)
+    .where(and(eq(pilots.playerId, playerId), eq(pilots.isAvatar, true)));
+  const [company] = await tx.select().from(companies).where(eq(companies.playerId, playerId));
+  if (!avatar || !company) throw new Error(`Player ${playerId} is missing its avatar or company`);
+
+  const loaner: ShipState = {
+    id: LOANER_SHIP_ID,
+    modelId: loanerModel(content).id,
+    locationId: player.loanerLocationId,
+    inFlight: false,
+  };
+  const pilot = pilotState(avatar);
+  const check = validateDispatch(
+    { ship: loaner, pilot, contract, tutorial: true, credits: company.credits, now },
+    content,
+  );
+  if (!check.ok) throw gameError(check.reason, VALIDATION_MESSAGES[check.reason]);
+
+  const record = createDispatchRecord(
+    {
+      id: randomUUID(),
+      ship: loaner,
+      pilot,
+      contract,
+      tutorial: true,
+      now,
+      worldSeed: player.worldSeed,
+    },
+    content,
+  );
+  const dispatch = await storeDispatch(tx, { playerId, record, shipId: null, periodIndex, now });
+  await tx
+    .update(pilots)
+    .set({ status: "in_flight", locationId: null })
+    .where(eq(pilots.id, avatar.id));
+  return dispatch;
+}
diff --git a/apps/server/src/game/messages.ts b/apps/server/src/game/messages.ts
new file mode 100644
index 0000000..d0b0a44
--- /dev/null
+++ b/apps/server/src/game/messages.ts
@@ -0,0 +1,18 @@
+import type { DispatchFailure, RepositionFailure } from "@deadhead/sim";
+
+/** Player-facing text for each sim validation reason. */
+export const VALIDATION_MESSAGES: Record<DispatchFailure | RepositionFailure, string> = {
+  "ship-not-idle": "That ship is already flying.",
+  "ship-not-at-origin": "That ship is not at the contract's pickup location.",
+  "pilot-not-idle": "That pilot is already flying.",
+  "pilot-not-assigned": "That pilot is not assigned to that ship.",
+  "over-capacity": "The cargo is too heavy for that ship.",
+  "cannot-land": "That ship cannot land at the destination.",
+  "out-of-range": "The destination is out of that ship's range right now.",
+  "cargo-skill-too-low": "The pilot's cargo skill is too low for this contract.",
+  "long-haul-too-low": "The pilot's Long Haul skill is too low for this distance.",
+  "contract-expired": "This contract has expired.",
+  "insufficient-credits": "Not enough credits for fuel.",
+  "already-there": "The ship is already there.",
+  "no-bay-at-destination": "You have no bay at that destination.",
+};
diff --git a/apps/server/src/http/errors.ts b/apps/server/src/http/errors.ts
index b0157c1..e3e5224 100644
--- a/apps/server/src/http/errors.ts
+++ b/apps/server/src/http/errors.ts
@@ -12,9 +12,15 @@ export class ApiError extends Error {
   }
 }
 
+const NOT_FOUND_CODES: ReadonlySet<ErrorCode> = new Set([
+  "not-found",
+  "unknown-contract",
+  "unknown-skill",
+]);
+
 /** A game-rule failure: 404 for unknown things, 409 for everything else. */
 export function gameError(code: ErrorCode, message: string): ApiError {
-  return new ApiError(code === "not-found" ? 404 : 409, code, message);
+  return new ApiError(NOT_FOUND_CODES.has(code) ? 404 : 409, code, message);
 }
 
 export function errorBody(code: ErrorCode, message: string): ErrorResponse {
diff --git a/apps/server/src/routes/dispatches.ts b/apps/server/src/routes/dispatches.ts
new file mode 100644
index 0000000..64e48d9
--- /dev/null
+++ b/apps/server/src/routes/dispatches.ts
@@ -0,0 +1,21 @@
+import { routes } from "@deadhead/schema";
+import type { FastifyInstance } from "fastify";
+import { dispatchTutorial } from "../game/dispatch";
+import { gameError } from "../http/errors";
+import { registerRoute } from "../http/route";
+import type { AppContext } from "./context";
+import { withPlayer } from "./with-player";
+
+/** Contract, tutorial and reposition dispatches. */
+export function registerDispatchRoutes(app: FastifyInstance, ctx: AppContext): void {
+  registerRoute(app, routes.createDispatch, ctx.options, async (input, { playerId }) =>
+    withPlayer(ctx, playerId, async (tx, now) => {
+      switch (input.kind) {
+        case "tutorial":
+          return { dispatch: await dispatchTutorial(tx, playerId, input.contractId, now) };
+        default:
+          throw gameError("not-found", `Dispatch kind "${input.kind}" is not available yet.`);
+      }
+    }),
+  );
+}
diff --git a/apps/server/test/tutorial-dispatch.test.ts b/apps/server/test/tutorial-dispatch.test.ts
new file mode 100644
index 0000000..6d46389
--- /dev/null
+++ b/apps/server/test/tutorial-dispatch.test.ts
@@ -0,0 +1,105 @@
+import { content } from "@deadhead/content";
+import {
+  contractBoardResponseSchema,
+  dispatchResponseSchema,
+  errorResponseSchema,
+} from "@deadhead/schema";
+import { MS_PER_HOUR, travelTimeGameHours } from "@deadhead/sim";
+import { describe, expect, it } from "vitest";
+import { useTestDatabase } from "./db";
+import { call, getState, signUp, useTestApp, type Guest } from "./game";
+
+const database = useTestDatabase();
+const testApp = useTestApp(database);
+
+async function tutorialBoard(guest: Guest) {
+  const response = await call(testApp().app, guest, "GET", "/api/tutorial/board");
+  return contractBoardResponseSchema.parse(response.json()).contracts;
+}
+
+function flyTutorial(guest: Guest, contractId: string) {
+  return call(testApp().app, guest, "POST", "/api/dispatches", { kind: "tutorial", contractId });
+}
+
+describe("tutorial dispatch", () => {
+  it("dispatches the avatar in the loaner, charging no fuel", async () => {
+    const { app, clock } = testApp();
+    const guest = await signUp(app);
+    const [contract] = await tutorialBoard(guest);
+
+    const response = await flyTutorial(guest, contract!.id);
+    expect(response.statusCode).toBe(200);
+    const { dispatch } = dispatchResponseSchema.parse(response.json());
+
+    expect(dispatch).toMatchObject({
+      tutorial: true,
+      status: "in-flight",
+      originId: "earth",
+      destinationId: "moon",
+      pilotId: guest.avatarId,
+      fuelCost: 0,
+      departureAt: clock.now,
+      expectedPayout: contract!.payout,
+    });
+    const travelMs =
+      (travelTimeGameHours(content.shipModel("courier")!, dispatch.distanceMillionKm) *
+        MS_PER_HOUR) /
+      content.config.timeCompression;
+    expect(dispatch.arrivalAt - dispatch.departureAt).toBe(Math.round(travelMs));
+
+    const state = await getState(app, guest);
+    expect(state.company.credits).toBe(content.config.startingCredits);
+    expect(state.tutorial).toEqual({ loanerLocationId: "earth", runInFlight: true });
+    expect(state.pilots[0]).toMatchObject({ status: "in-flight", locationId: null });
+    expect(state.activeDispatches.map((d) => d.id)).toEqual([dispatch.id]);
+    expect((await tutorialBoard(guest)).map((c) => c.id)).not.toContain(contract!.id);
+  });
+
+  it("rejects a second tutorial run while one is in flight", async () => {
+    const { app } = testApp();
+    const guest = await signUp(app);
+    const [first, second] = await tutorialBoard(guest);
+    await flyTutorial(guest, first!.id);
+
+    const response = await flyTutorial(guest, second!.id);
+    expect(response.statusCode).toBe(409);
+    expect(errorResponseSchema.parse(response.json()).error.code).toBe("tutorial-run-in-flight");
+  });
+
+  it("pays exactly the tutorial share on arrival and moves the loaner and avatar to the Moon", async () => {
+    const { app, clock } = testApp();
+    const guest = await signUp(app);
+    const [contract] = await tutorialBoard(guest);
+    const { dispatch } = dispatchResponseSchema.parse(
+      (await flyTutorial(guest, contract!.id)).json(),
+    );
+
+    clock.now = dispatch.arrivalAt;
+    const state = await getState(app, guest);
+    expect(state.company.credits).toBe(content.config.startingCredits + contract!.payout);
+    expect(state.pilots[0]!.xp).toBeGreaterThan(0);
+    expect(state.pilots[0]).toMatchObject({ status: "idle", locationId: "moon" });
+    expect(state.tutorial).toEqual({ loanerLocationId: "moon", runInFlight: false });
+
+    const next = await tutorialBoard(guest);
+    expect(next.length).toBeGreaterThan(0);
+    for (const c of next) expect([c.originId, c.destinationId]).toEqual(["moon", "earth"]);
+  });
+
+  it("rejects unknown and already-taken contracts", async () => {
+    const { app, clock } = testApp();
+    const guest = await signUp(app);
+    const [contract] = await tutorialBoard(guest);
+
+    const unknown = await flyTutorial(guest, "tutorial:earth:0:999");
+    expect(unknown.statusCode).toBe(404);
+    expect(errorResponseSchema.parse(unknown.json()).error.code).toBe("unknown-contract");
+
+    const { dispatch } = dispatchResponseSchema.parse(
+      (await flyTutorial(guest, contract!.id)).json(),
+    );
+    clock.now = dispatch.arrivalAt;
+    const again = await flyTutorial(guest, contract!.id);
+    expect(errorResponseSchema.parse(again.json()).error.code).toBe("contract-already-accepted");
+  });
+});
diff --git a/memory-bank/progress.md b/memory-bank/progress.md
index 623b708..e59c4ce 100644
--- a/memory-bank/progress.md
+++ b/memory-bank/progress.md
@@ -57,7 +57,7 @@
 - [x] **Step 6.1 — Lazy resolution on read.** `resolveArrivedDispatches` (`src/game/resolve.ts`) resolves arrived dispatches in arrival order inside `withPlayerLock` (`src/game/lock.ts`, a transaction holding the company row lock); a conditional status update makes each resolve exactly once. `GET /api/state` runs it before reading. Routes moved to `src/routes/`.
 - [x] **Step 6.2 — Get full player state.** Endpoint from Step 5.5 plus lazy resolution; test covers a player with one ship in flight and one idle (crewed by a hired pilot), checking ships, pilots (XP, level, skills, points, assignment, status, location), bays, dispatches, summaries and schema validity.
 - [x] **Step 6.3 — Tutorial board endpoint.** `GET /api/tutorial/board` (`src/routes/boards.ts`, `src/game/boards.ts`): stored per (period, loaner location) on first request, accepted contracts hidden, `409 not-in-tutorial` after the tutorial. Every game route now runs through `withPlayer` (lock + lazy resolution).
-- [ ] Step 6.4 — Tutorial dispatch
+- [x] **Step 6.4 — Tutorial dispatch.** `POST /api/dispatches` with `kind: "tutorial"` (`src/game/dispatch.ts`): avatar + loaner, sim validation, no fuel, one run at a time; contract marked accepted. Arrival pays the stored tutorial payout and moves loaner and avatar.
 - [ ] Step 6.5 — Buy a ship
 - [ ] Step 6.6 — Lease a bay
 - [ ] Step 6.7 — End tutorial